"My close friends and family know there are very few times when I'm left speechless... wow!" Payne wrote alongside a photo of himself holding his newborn son. "I'm incredibly happy to welcome our new baby boy into the world, it's a moment that I will never forget for the rest of my life and my favourite memory I have so far."
"I'm completely in awe of his incredible mother and how she has been the whole way through this, she's really made my dreams come true. We haven't named him yet but he's already capturing hearts including mine. I feel very blessed," he continued. "Happy Mother's Day everyone!"
Cole, too, took to Instagram to gush about her new son, who arrived just before British Mother's Day on Sunday.
"On Wednesday 22nd March, Liam and I became parents to an incredibly beautiful, healthy baby boy, weighing 7lb 9 and looking like a dream. Although he still doesn't have a name he is already stealing hearts," she shared. "We are all madly in love and overwhelmingly happy with our little arrival. Happy Mother's Day to all the mothers around the world. A day that now has a different meaning to me forever ?."
Payne, 23, and Cole, 33, have stayed out of the public eye for the most part during their pregnancy, but turned heads as the former X Factor judge debuted her baby bump at an event in November.